Adapter



y 1934- LE ROY J. LEISHMAN ,959,272

ADAPTER Original Filed 001;. 6, 1927 2% gmentom Zero JLea'akmarb,

Patented May 15, 1934 ADAPTER Le Roy J. Leishman, Los Angeles, Calif.Original application. October 6,1927, Serial No.

224,468.. Divided and this application March 13, 1930, Serial No.435,525

9 Claims.

This invention relates to electrical reproducers, and primarily to asimple and efficient apparatus: for connecting. an electrical pick-upfor phonographs: or telegraphone. sound box with 5, the circuits of aradio receiving set so: as to. utilize. the amplifier system thereof forreproducing phonograph selections Without materially altering thecircuits of the radio set. or interfering with its: use as a receiver ofradio signals at other times.

This application isa division of my application, Serial No. 224,468,filed October 6, 192? patented. Feb. 9,, 1932,, Patent No. 1,844.583.

In accordance with this invention provisions 1' are made for connectingan electrical pick-up for phonographs or telegraphone sound box eitherwith the grid circuit or the plate circuit of the detector tube of theradio set, preferably the grid circuit. In order to connect conven- 2'iently the electrical pick-up with the radio set Without. altering anyof the connections of the set, an apertured disk is used which fits theprongs of the detector tube between the tube and the contacts of thedetector tube socket,

making electrical connection with either the plate prong or the gridprong. and also with the cathode prong when the usual AC tube is used orwith one of the filament prongs if the old A battery tube is used.

3 The invention will be described in detail in connection with theaccompanying drawing and.

hereinafter claimed. In the drawing: Figure 1 is a circuit diagramshowing the manner of connecting a phonograph electrical pickup with thedetector grid circuit of a radio receiving set in. accordance with myinvention.

Figure 2 is an elevation view of the lower portion of a radio: detectortube with a disk in section to show contacts carried thereby for makingconnections with the pick-up in accordance with this invention.

Figure 3 is a plan view of the contact disk. Referring to the drawing,Figure 1 shows the detector and first stage of the audio amplifier onlyof any standard type of' radio receiving set employing a detector andone or more stages of audio amplification- The detector tube isgenerally designated by the reference numeral 11 and the first audiotransformer 12. The set is supplied with electrical energy at the properpotentials, thesources shown being A and B batteries, and the detectorcircuit may be equipped with the usual grid leak resistance 14 and gridcondenser 13.

In accordance with the present invention an electrical pick-up forphonographs or telegraphone sound box 15 is connected with the radioreceiving set so: as to utilize the amplifier system thereof forreproducing phonograph selections. Since the detector tube will remainin its socket, and the circuit is not broken in any place, radio signalswill come thru unless one of the radio frequency tubes is removed or, aswill usually be the case, unless the set is detuned. While I haveillustrated the set using both A and B batteries, the tubes usuallyemployedwil'l. be the more modern AC tubes.

The electrical pick-up 15 is provided with a connecting cable shown aswires 16 which provide electrical connections for it with the gridcircuit of the radio set by means of a plug 17 which is adapted to beinserted in a jack 18 the terminals of which are connected with the gridand the cathode terminals of the detector tube 11 preferably by means ofthe connector dem scribed in the next paragraph. Between the wires 16 ofthe connecting cable a small case 1-9 is provided in which is a bypasscondenser 20 of approximately one microfarad and a va riable modulatingresistance 21. This case 19 go is. a standard unit providing a blockingcondenser which is necessary in case the reproducer is connected to theplate terminals of the detector tube instead of to the. grid terminal aspreferred.

A connector for the electrical pick-up preferably includes a very simpleform of connection which consists of a disk 22 shown in Figures 2 and 3.This connector or disk has four or fi-ve holes for receiving the prongsof the detector tube 11, depending on whether battery or AC tubes: areused. Inthe battery type, for example, one of the holes for the filamentterminals such as the one receiving the prong 23. and either the plateor the grid hole, according as to whetherthe circuit of the pick-up isto be made with the grid circuit or plate circuit of the detector of theradio set, are placed contacts 24 which engage the tube prongs, and leadwires 25 and 26 are connected to these contacts. No means; of fastening,the contacts to the disk or plate are shown sinceit is obvious that theymay be cemented, rivetedv or clamped to the. plate or they may befastened thereto by any other of the. means now well known to thoseskilled. in this type; of work, but the method and means for fasteningthem in place in no way involves'the present: invention and is not beingclaimed. The connector is very similar tov my ordinary adapter, butprovides simple and efiicient means for making connection with the tubeprongs with the tube in place in the tube socket without materiallydisplacing the tube or taking up a great amount of space in the radioreceiving set, as the disk 22 slips on the base of the detector tube andthe leads are sufiiciently small and flexible to fiteasily between thetube and the old-fashioned socket should the latter be used. It isunderstood that the lead wires 25 and 26 are of ample length soas to beused as flexible connections between the radio set and any accessoriesthat may be used as, for example, pick ups and the like.

In Figure 1, the preferred arrangement, the phonograph pick-up ortelegraphone is shown connected with the grid circuit of the detectortube, thus utilizing the amplifying efiect of this tube as well as theaudio amplifiers and by means of its connection therewith excluding thepassage of radio frequency currents to the detector tube. However, asabove referred to, the connections could as readily be made with theplate circuit of this tube by arranging the contacts 24 of the disk forsuch plate circuit connections in which event the blocking condenser 20in the case 19 is necessary. The standard case 19 with the condenser andvariable resistance are shown in the circuit of the pick-up forconnection with the grid circuit (Figure 1) the condenser although notessential in this circuit is not objectionable and is retained in thecircuit as a matter of convenience as a part of the standard equipment.

What I claim is:

1. An adapter for tapping a circuit of a radio receiving set consistingof a disk and a conductor leading therefrom, said disk having aperturesto fit over the prongs of a radio tube, and a single contact membercarried by said disk, and

" arranged in one of said apertures providing a terminal connection forsaid lead conductor, said disk being relatively thin with respect to thelength of the prongs of the radio tube, whereby the adapter may liebetween the base of a pronged radio tube and its socket and permit theprongs of the tube to engage their usual socket contacts.

2. An adapter for tapping certain tube circuits of a radio receivingset, said adapter hav- -ing apertures to permit all the prongs of apronged base radio tube to pass therethru and having a thickness whichis small with respect to the length of the prongs thereby to permit theprongs to make their normal connections in the regular tube mounting inthe radio set while the adapter is in operative position between thebase of the tube and said mounting, said adapter comprising contactsadapted to engage the prongs passing thru said apertures and aninsulating contact-supporting member to insulate and position saidcontacts, each of said contacts positioned to engage a predeterminedsingle tube prong and to provide terminal connections for leadconductors from the radio receiving set.

3. An adapter for tapping a tube circuit of a radio receiving setcomprising the combination of a conductor, a resilient contact and asubstantially fiat insulating member adapted when assembled to liebetween the base of a pronged tube and its regular mounting in a radioreceiving set, said member being thin with respect to the length of thetube prongs and having recesses to permit the tube prongs to pass beyondthe plane of said insulating member and to extend sufiiciently far tomake their normal connections in the regular tube mounting; and saidresilient contact being attached to said insulating member providing aterminal connection for said conductor, said contact positioned adjacentone of said recesses to engage a predetermined single prong of the tube.

4. An adapter for making a circuit connection with a radio tube of theprong base type while said tube is positioned in its regular mounting ina radio receiving set, said adapter comprising a contact-supportingmember, apertured to permit all the prongs of the tube to pass thru saidmember to make their normal connections in a regular tube socket of aradio receiving set, and a contact carried by said member providing aterminal connection for a lead conductor, said contact positioned toengage a predetermined single prong of the tube.

5. A wafer adapter for making an electrical connection in parallel withcertain tube circuits of a radio receiving set, comprising an insulatingcontact-supporting member apertured to permit all the prongs of a radiotube to pass therethru and to make their normal connections in theregular tube socket; and resilient contacts supported by said memberproviding terminal connections for lead conductors, each of whichcontacts is positioned on said member so as to engage a respectivelydifferent single prong of the tube passing through said member.

6. An adapter for tapping certain tube circuits of a radio receiving setconsisting of a flat insulating member having apertures to receive theprongs of a radio tube, said member being thin with respect to thelength of the tube prongs thereby permitting the prongs to extend therethrough and engage in their regular sockets in the receiving set, and acontact member in one of said apertures, a separate contact member in asecond aperture, said contact members pro-' viding terminal connectionsfor lead conductors, said two contact members each projecting into saidapertures in a downwardly extending direction so that as a prong entersthe aperture it will force the contact member toward the wall of theaperture.

7. An adapter for tapping certain tube circuits of a radio receiving setwhile saidtube is connected in its normal operating position, comprisinga wafer like body, said body having apertures to permit tube prongs topass therethru and to make their normal connections in the rgular prongsockets, and resilient contacts adapted to engage the sides of the tubeprongs passing thru said apertures, said contacts providing terminalconnections for lead conductors.

8. An adapter for tapping certain tube circuits of a radio receivingset, said adapter comprising a wafer like body of insulation aperturedto permit tube prongs to pass therethru, and resilient contacts carriedby and so positioned on said body as to engage the sides of respectiveselected prongs of the tube, a portion of said adapter being adapted tolie under a tube base, said portion being thin with respect to thelength of the tube prongs so as to occupy a small axial space under thetube whereby when in operative position it permits all the prongs of thetube to engage in their usual prong sockets in a radio set, saidcontacts providing terminal connections for lead conductors.

9. An adapter for tapping certain tube circuits of a radio receiving setconsisting of an insueach projecting into said apertures in a downwardlyextending direction so that as a prong enters the aperture it will forcethe contact member against the wall of the aperture.

LE ROY J. LEISHMAN.

